A Massachusetts General Hospital neuroscientist is designing a prosthetic to bypass eyes and optic nerves and send image information directly to the regions of the brain that processes visual signals.

The prosthesis proposed by John Pezaris would be worn like a pair of glasses, with digital cameras over a person's eyes connecting to an array of electrodes implanted in the brain.

Essentially the ?Virtual Light? goggle concept, finally brought into reality (hopefully). In research published in 2007 Pezaris and other researchers were able to show that microstimulation in certain areas of the brain creates a percept that the brain interprets as optical input, or something that can be "seen."

The technology still has a lot of obstacles to overcome:

* Digital imaging that can substitute for normal vision
* Conquering and understanding all the brain signal codes the eye uses to communicate with the brain
* The risk of infection from brain surgery
* Maintaining long-term signal strength in a deep-brain implant.

"We've been working on trying to understand more about the percepts, or visual events, we're creating," Pezaris says, including what images look like, how big they are, how long they appear and whether they are in colour or black and white. "We don't have a really solid handle on any of this now."

Such detractions aside, success would have a liberating, life-altering impact on the tens of millions of people world wide suffering from impaired vision, and enable sight retention even if the eyes were themselves destroyed.